Furnace silencers

ABSTRACT

The noise generated by the burners of industrial furnaces is suppressed by attaching to the bottom of the furnace below the burners a chamber which is internally insulated with acoustical insulation means and which is provided with at least one similarly insulated baffle member over which the air fed to the burners must flow from adjustable dampened air intake means. The bottom of the chamber is provided with the air intake means and with outwardly openable inwardly insulated doors providing access to the furnace burners during operation.

United States Patent 1 Poepsel et al.

[111 3,748,085 July 24, 1973 FURNACE SILENCERS [76] Inventors: James R. Poepsel, 1410 Greenwood Dr.; Paul S. Weber, 1410 Sherwood, both of Baytown, Tex. 77520 [22] Filedi Mar. 10, 1972 [21] Appl. No.: 233,702

[52] US. Cl. 431/114 [51] Int. Cl. F23c 7/04 [58] Field of Search 431/114; 110/175 R, 110/175 A [5 6] References Cited UNITED STATES PATENTS 2,781,829 2/1957 Zucker et a1. 431/114 2,964,121 12/1960 Zink et al. 431/114 3,684,424 8/1972 Zink et al. 431/114 LL $135 26 23 I Primary Examiner-Edward G. Favors Attorney-Thomas B. McCulloch et al.

[57] ABSTRACT The noise generated by the burners of industrial furnaces is suppressed by attaching to the bottom of the furnace below the burners a chamber which is internally insulated with acoustical insulation means and which is provided with at least one similarly insulated baffle member over which the air fed to the burners must flow from adjustable dampened air intake means. The bottom of the chamber is provided with the air intake means and with outwardly openable inwardly insulated doors providing access to the furnace burners during operation.

10 Claims, 3 Drawing Figures Petented July 24, 1973 FIG.

Furnace 30 FIG; 2.

H Flow Metal Screen 22 Fiber Glass 20 Asbestos Cloth 2| FIG.3.

FURNACE SILENCERS- BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a silencer for furnaces. More particularly, it is directed to a silencer for furnace burners which is readily installed while the burners are accessible. In its more specific aspects, the invention is concerned with apparatus for silencing the noise generated by industrial furnaces which is easily installed and is quite effective.

2. Description of the Prior Art It is known to employ plenum chambers on furnaces. It is also known to provide a silencer chamber for flowing streams of air of other gases. Such latter chambers are constructed in part of acoustical insulation material which may be retained in place by screen wire mesh. Direction of the flow of fluid prior to exit by a baffle is also taught.

Likewise, plenum chambers with trap doors for admitting air into the bottom portion of furnaces have been taught in the art. The use of dampeners in air intakes is also taught. However, it has not been taught or made obvious from the prior art to provide a silencer for an industrial furnace which is easily installed and which decreases the noise generated by the burners to a point where the furnace now operates quietly without noise hazard to personnel. The present invention is, therefore, new, useful and unobvious, and therefore patentable. 1

The following references tion with this invention;

U. S. PAT. NOS.

SUMMARY OF THE INVENTION 'The invention may be briefly described and summarized as a silencer for industrial furnaces which-may be re'movably or fixedly attached to a furnace. The silencer comprises a'chamber or chambers, preferably rectangular, havingspaced from air intake or intakes a baffle member extending across the chamber and extending a sufficient distance substantially below the open upper end of the chamber which communicates with the burners and which is attached to the furnace. The rectangular walls of the chamber are constructed preferably of ferrous metal and are lined in the order given with acoustical insulation material, which'may be fiber glass, optionally heat insulation material over the acoustical insulation material to protect the acoustical material from deterioration caused by air velocity and any handling which may occur. The asbestos cloth used as heat insulation material also protects the fiber glass from hot particles which may drop into the chamber were considered in connecsince the air flow keeps \the-chamber relatively cool.

Expanded metal'm'eshisused over'the heat insulation material. The heat insulation material is preferably asbestos cloth.

BRIEF DESCRIPTION OF THE DRAWING The invention will be further illustrated by reference to the drawing in which:

FIG. 1 is a perspective view of the silencer of the present invention showing the location of the baffle members and the air intakes;

FIG. 2 is an elevational view of the device installed on a furnace;

FIG. 3 is a fragmentary sectional view along line 3-3 of FIG. 2 showing the wall and bottom door structure.

DESCRIPTION OF THE PREFERRED MODE AND EMBODIMENT RELATIVE TO THE DRAWING Referring now to the drawing, in which identical numerals designate identical parts, numeral 11 designates a plenum chamber formed of wall members 12 and-l2a suitably constructed of steel or other heat resistant metal. The wall members 12 and 12a may be constructed of other ferrous metal or alloys of ferrous metal and the like. Baffle members 13 extend across from side wall members 12a and may be spaced about 1 to 12 inches from end wall members 12; the wall members 12a may extend from the floor of chamber 11 about 2 to 4 feet and have lengths from about 5 to 50 feet. Baffle members 13 may extend from the floor of chamber 11 about 6' to 36 inches.

The bottom 14 of chamber 11 is comprised of out wardly swinging hinged doors 15 which are connected to side wall members 12 by hinges 16. The doors 15 are constructed of aluminum sheet 17 connected to an aluminum L-shaped member 18 which in turn is connected to hinge 16. g

Referring now to FIGS. 1 and 3, the inner walls 12 and 12a, baffles 13 and doors 15 are covered, respectively, in'the order givenwith fiber glass (acoustical) insulation 20, asbestos cloth (heat) insulation 21, and expanded metal mesh 22, all of which is connected to the walls 12 and 12a and the baffles 13 by metal straps 23. Means 24areprovidedforattachment to the bottom floor 31 of a furnace 30 and immediately below the burners not shown.

The doors 15, forming bottom 14, may close against a door jamb or sea] 25 to which they may be bolted as the doors are only opened during performance of maintenance.

Air intakes 26 with hinged damper blades 27 are also provided at least with acoustical insulation means and are arranged between end walls 12 and baffle members 13 as shown in FIGS. 1 and 2. The air intake means 26 are between the baffle members 13 and the end walls 12 such that air-flow is up and over the baffle members 13. Means 28 allow adjustment of the damper blades 27 position. The damper blades regulate the size of the air intake means which may range from about -l ,10 about 12 inches and the chamber is so sized and ofa depth selected to provide a velocity of flow through the chamber as shown by the arrows in FIG. 3 less than that which causes the furnace to operate inefficiently. A velocity of about 3 to feet per second may be employed.

Thus, prior to the installation of the present invention, the noise generated by furnace burners was so loud that acoustical protection devices were needed by the operators whereas after installation of the present invention the noise had been decreased to an extent that such devices were not needed.

While the silencer of the present invention is detachable from the furnace, it may be made'an integral part thereof. Likewise, while a rectangular silencer and vertical furnace have been described and operated, the silencer may be cylindrical or otherwise conform to the shape of the furnace or configuration of the burners thereof. Also, specific insulation means both heat and acoustical have been illustrated. The invention is not confined to those illustrated. The insulation means may be attached to the walls and baffle means of the silencers by heat resistant adhesives, metal mesh, wire, straps, and the like.

The nature and objects of the present invention having been fully described and illustrated and the best mode and embodiment contemplated set forth, what we wish to claim as new and useful is:

We claim:

1. Apparatus for attachment to the bottom of a furnace having burners which generate noise which comprises:

wall means forming an open-ended chamber attachable at the open end to said furnace below the.

burners;

at least acoustical insulation means lining the inner wall of said chamber;

hinged doors forming the bottom of said chamber connected to said chamber and adapted to swing outwardly;

- the inner side of said doors being lined at least with acoustical insulation means;

at least a baffle member spaced from the inner sur- I V the furnace to operate inefficiently.

. 2. Apparatus in accordance with claim 1 in which the chamber forming means is removably attached to the furnace.

3. Apparatus in accordance with claim 1 in which the chamber forming means is fixedly attached to the furnace.

4. Apparatus in accordance with claim 1 in which the chamber is rectangular.

5. Apparatus in accordance with claim 1 in which the doors are formed of aluminum inner lined with acoustical insulation means.

6. Apparatus in accordance with claim 1 in which the acoustical means is covered by heat insulation means which in turn is covered with metal mesh means.

7. Apparatus in accordance with claim 6 in which the heat insulation means covering said acoustical insulation means is asbestos cloth. A

8. Apparatus in accordance with claim 6 in which the mesh'means is expanded metal mesh.

9. Apparatus in accordance with claim 1 in which the chamber is rectangular and has a depth in the range from about 2 to about 4 feet, the size of the air intake means is controlled by said dampers in'the range between about 1 and 12 inches, and the air intake means is arranged between the baffle member and a wall of said chamber.

10. Apparatus in accordance with claim 1 in which acoustical insulation means is fiber glass insulation. 

1. Apparatus for attachment to the bottom of a furnace having burners which generate noise which comprises: wall means forming an open-ended chamber attachable at the open end to said furnace below the burners; at least acoustical insulation means lining the inner wall of said chamber; hinged doors forming the bottom of said chamber connected to said chamber and adapted to swing outwardly; the inner side of said doors being lined at least with acoustical insulation means; at least a baffle member spaced from the inner surface of said wall means of and extending parallel across said chamber a distance substantially below the open end of the wall means; said baffle member having at least acoustical insulation means covering it; air intake means formed in said chamber such that air flow to said burners is over said baffle member; and adjustable dampers in said air intake means; the size of the air intake means and the depth of the chamber being selected to provide a velocity through the chamber less than that which causes the furnace to operate inefficiently.
 2. Apparatus in accordance with claim 1 in which the chamber forming means is removably attached to the furnace.
 3. Apparatus in accordance with claim 1 in which the chamber forming means is fixedly attached to the furnace.
 4. Apparatus in accordance with claim 1 in which the chamber is rectangular.
 5. Apparatus in accordance with claim 1 in which the doors are formed of aluminum inner lined with acoustical insulation means.
 6. Apparatus in accordance with claim 1 in which the acoustical means is covered by heat insulation means which in turn is covered with metal mesh means.
 7. Apparatus in accordance with claim 6 in which the heat insulation means covering said acoustical insulation means is asbestos cloth.
 8. Apparatus in accordance with claim 6 in which the mesh means is expanded metal mesh.
 9. Apparatus in accordance with claim 1 in which the chamber is rectangular and has a depth in the range from about 2 to about 4 feet, the size of the air intake means is controlled by said dampers in the range between about 1 and 12 inches, and the air intake means is arranged between the baffle member and a wall of said chamber.
 10. Apparatus in accordance with claim 1 in which acoustical insulation means is fiber glass insulation. 